Actually, this is written into many classical-era scores, including many by Mozart or Haydn. I think the finale to Mozart's 40th loses a lot if the second half isn't repeated, and my favorite joke in the first movement of Mozart's Musical Joke is lost if you don't take the second repeat.I have nothing against repeats, as I usually tend to enjoy them a great deal, so long as they do not extend beyond the exposition. Some conductors take great liberty in repeating the development section/s, which I find unnecessary and to me, it takes away whatever momentum the piece has built up. So yeah, repeat the exposition, but please do not do the same to the development section/s.
Perhaps it goes without saying, but I think the repeats in Mahler's works (the exposition of the First and Sixth Symphonies' first movements, the first part of the First's scherzo) should be taken for reasons of balance. The exposition repeat in the Fifth, which was removed by Mahler but remains in scores based on the first printing, is better off not taken.